It is well known that the application of a lubricant to the surfaces of railroad tracks improve the rollability of railroad cars thereby significantly reducing the rate at which the tracks become worn by the wheels of the cars which move along them. Lubricating the tracks also reduces the wear to the wheels of the cars. Curves and switches are particularly subject to wear.
The cars of a train are disassembled and reassembled into new trains in a yard which has numerous parallel tracks that are accessible from the opposing ends thereof by access tracks connected by switches. The track, including curves and switches, are currently lubricated by injecting a lubricant through outlets on to the surface of the tracks.
Within the yard the cars of an incoming train are disassembled and recombined with cars from other incoming trains into a plurality of new outgoing trains, with the cars of each new train lined up on a separate track in the yard. One method is a hump yard for such purposes, where a switch engine moves a car over a hump at a speed of approximately three miles per hour. The cars are independently released on the crest of the hump and allowed to roll down the far side of the hump and across switches to tracks on which the new trains are being formed.
In a hump yard, the speed of the car as it moves along the track system is controlled by a series of retarders. A computer associated with each retarder receives information regarding the weight of the incoming car and has a sensor for determining the speed at which the car is entering the retarder. It also maintains a count of the number of cars being directed to each yard track and adjusts the application of the retarder based on the incoming speed, the wright of the approaching car and the space remaining on the yard track. Other sensors in the system follow the car's progress across the switches of this system and prohibit the premature throwing a switch along the path of a rolling railroad car. Except for weight, the retarders of a hump yard system are not responsive to the condition of an individual car or to the condition of the track.
The dispensers now being used to lubricate the tracks of a yard system have an associated detector for detecting that a car is approaching and the dispenser dispenses a fixed amount of lubricant each time a car passes. When the tracks are properly lubricated, a railroad car that does not have its brake applied and is free of defects will move along the tracks of the system at a predictable rate. In reality, however, several factors affect the amount of lubricant needed to maintain the optimum rollability of cars over the tracks. Over lubrication will cause excess lubricant to build up in the yard tracks. Excess lubricant is a hazard to railroad personnel, can cause roll out, can cause damage to the cars and the contents thereof, and contaminates the underlying ground.
Water is a natural lubricant and, therefore, a lesser amount of lubricant is needed on the tracks during rain or snow. On the other hand, rain or snow will wash some of the lubricant off the tracks leaving the tracks in need of restoration of the desired level of lubrication after the rain has ended. Cars moving along the tracks of an adequately lubricated yard system will lose speed at a predictable rate thereby allowing the orderly assembly of the cars on the yard tracks. On the other hand, the cars move more slowly along inadequately lubricated tracks, as occurs following a rain storm.
Lubricant which is dispensed on the track is picked up by the wheels of a moving railroad car and spread down the track. Once a few cars have applied lubricant to a previously under lubricated track, the cars will again begin moving at their desired speeds, after which only intermittent application of lubricant are needed to maintain adequate lubrication. It is unnecessary, therefore to apply lubricant to the tracks each time a car is released over a hump as currently done in a hump yard.
All of the foregoing problems could be reduced or eliminated by providing a means of measuring the need for lubricant on the tracks of a yard system and controlling the application of lubricant in response to the measured need. Until the present invention, the railroad industry has not had such a means for measuring the need for lubricant on the tracks of a yard system.